Integrated optical spectrum analyzer based on planar optical waveguide and its application

Abstract

The present invention discloses an integrated optical spectrum analyzer based on a planar optical waveguide and its application. The integrated optical spectrum analyzer includes: a periodic narrowband filtering module for performing periodic narrowband filtering on an input optical signal to obtain a single-channel multi-passband narrowband optical signal; a demultiplexing module for receiving the single-channel multi-passband narrowband optical signal and separating the multi-passband narrowband optical signals therein so that each passband is output to its different output; a detector array for converting the received optical signal into an electrical signal; and a control and data processing module for performing analog-to-digital conversion and data processing on the electrical signals output by each detector unit. The present invention utilizes a periodic narrowband filtering module for fine filtering, a demultiplexing module for multi-passband separation, a detector array for photoelectric conversion, and a control and data processing module for control and data processing. Spectral analysis is completed through the coordinated operation of multiple modules, and has the advantages of small size, high integration, high resolution, and fast scanning speed.

Description

Technical Field

[0001] The present invention relates to the technical field of miniaturized and portable spectrum analyzers, and in particular to an integrated spectrum analyzer based on a planar optical waveguide and applications thereof. Background Art

[0002] In fields such as agricultural production, food manufacturing, biomedicine, resource exploration, and petrochemicals, it is often necessary to perform transmission or reflection spectral analysis of various substances, including gases, liquids, and solids, across different wavelengths to determine their composition and content. Miniaturized, handheld, and portable on-site rapid analysis spectrometers are economical, efficient, and flexible spectral analysis tools. Compared to traditional desktop spectrometers, they offer advantages such as small size, light weight, low power consumption, and low cost, making them easy to develop. They are in urgent demand in these production and research fields.

[0003] Currently commercially available or publicly available miniaturized, handheld, and portable optical spectrum analyzers are typically constructed using modules such as diffraction gratings, micro-electromechanical systems, and bulk interferometers. However, these miniaturized optical spectrum analyzers still suffer from various limitations in terms of size, weight, and resolution, making them difficult to meet the demand for portable optical spectrum analyzers in various fields, such as agriculture, industry, and healthcare. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] In view of this, the main object of the present invention is to provide an integrated optical spectrum analyzer based on a planar optical waveguide and its application, so as to realize spectral analysis of light waves with different wavelength components and improve spectral resolution and scanning speed.

[0006] (2) Technical solution

[0007] To achieve the above object, the present invention provides an integrated optical spectrum analyzer based on a planar optical waveguide, comprising:

[0008] The periodic narrowband filtering module 100 is used to perform periodic narrowband filtering on the input optical signal to be measured to obtain a single-channel multi-passband narrowband optical signal;

[0009] The demultiplexing module 200 is used to separate the single-channel multi-pass narrowband optical signal received from the periodic narrowband filtering module 100, and separate the single-channel multi-pass narrowband optical signal into two N Each optical signal contains a passband, and each passband is output from a different output, where N ≥ 1;

[0010] The detector array 300 is used to detect the 2 N Convert the optical signal into an electrical signal and output it; and

[0011] The control and data processing module 400 is used to control the periodic narrowband filtering module 100 and the demultiplexing module 200, so that the filter passband of the periodic narrowband filtering module 100 moves step by step, and the filter passband of the demultiplexing module 200 moves synchronously with the filter passband of the periodic narrowband filtering module 100. Each time it moves, the control and data processing module 400 receives 2 signals from the detector array 300. N The electrical signals are converted into analog-to-digital and processed, and after the movement is completed, the spectrum of the input optical signal is synthesized.

[0012] In the above scheme, the periodic narrowband filtering module 100 is composed of a tunable micro-ring resonator unit, which receives the optical signal to be measured and performs periodic narrowband filtering on the received optical signal to be measured to obtain a single-channel multi-passband narrowband optical signal with a passband number of 2. N .

[0013] In the above scheme, the periodic narrowband filter module 100 is composed of a combination of several tunable microring resonators, or a combination of several tunable microring resonators and tunable microdisk resonators, and includes one main function inlet as the input port of the optical signal, one main function outlet as the output port of the optical signal, and several auxiliary test ports for calibrating, calibrating and monitoring each component unit.

[0014] In the above solution, due to the material dispersion and waveguide dispersion, the 2 N In a narrowband optical signal, the wavelength interval Δλ between the center wavelength of the i-th passband and the center wavelength of the i+1-th passband i Non-fixed value, where 1≤i≤2 N -1, and its maximum value, minimum value and average value are respectively referred to as the maximum free spectral range, the minimum free spectral range and the average free spectral range of the periodic narrowband filtering module (100).

[0015] In the above solution, the demultiplexing module 200 is composed of 2 N -1 Mach-Zehnder interferometer unit is cascaded in the form of an N-level binary tree, and the j-th level along the direction of optical transmission contains 2 (j-1) Mach-Zehnder interferometer units, where 1≤j≤N.

[0016] In the above solution, the demultiplexing module 200 includes 2 N - a Mach-Zehnder interferometer unit for converting two of the multi-band, quasi-periodic narrowband optical signals from the periodic narrowband filtering module 100 into N The passband separation is 2 N Each independent optical signal has a passband and is output to a detector unit of the detector array 300.

[0017] In the above solution, the demultiplexing module 200 is implemented by using a metasurface and sub-wavelength grating structure, and includes a main function entrance as an input port of the optical signal, and two N The main function ports serve as the output ports of optical signals, and several auxiliary test ports are used to calibrate, calibrate and monitor the Mach-Zehnder interferometer unit.

[0018] In the above solution, the detector array 300 includes 2 N A detector unit is used to receive the 2 separated signals from the demultiplexing module 200. N The optical signals are converted into electrical signals and output to the control and data processing module 400.

[0019] In the above solution, when the control and data processing module 400 controls the movement of the periodic narrowband filter module 100 and the demultiplexing module 200, each time the movement is performed, the filter passband positions of the periodic narrowband filter module 100 and the demultiplexing module 200 are moved in the same direction by a certain distance Δλ. s Each time it moves, the detector array 300 outputs 2 N Photocurrent; a total of M-1 moves to obtain M×2 N Photocurrent data, where M>1; the value of M satisfies the following relationship: (M-1)×Δλ s < the maximum free spectral range of the periodic narrowband filter module 100, and M×Δλ s ≥The maximum free spectral range of the periodic narrowband filter module 100.

[0020] In the above solution, the control and data processing module 400 has 2 N Each time, it receives 2 N analog electrical signals, received M times to obtain M×2 N electrical signals, for this M×2 N The electrical signal is converted into analog and digital and data processed.

[0021] In the above scheme, when the filter passband of the periodic narrowband filter module 100 is moved in a step-by-step manner, the filter passband of the demultiplexing module 200 does not follow the movement; when an optical signal with known spectral information is input, only the periodic narrowband filter module 100 is scanned and tuned to obtain the output of the detector array 300; using machine learning methods, by changing the spectrum of the input optical signal, a large number of input and output combinations are obtained, which are used to train the neural network, so that the integrated optical spectrum analyzer can obtain the spectrum of the optical signal to be measured through the trained neural network when the demultiplexing module 200 does not follow the tuning of the periodic narrowband filter module 100.

[0022] In the above scheme, the periodic narrowband filtering module 100, the demultiplexing module 200, and the detector array 300 are monolithically integrated chips and are manufactured on a common substrate material through compatible processes; or the periodic narrowband filtering module 100, the demultiplexing module 200, and the detector array 300 are respectively implemented by independent chips and integrated into a system through packaging.

[0023] To achieve the above objectives, the present invention also provides an application of the integrated optical spectrum analyzer based on a planar optical waveguide, comprising: utilizing a polarization-independent end coupler to receive external input light; utilizing an on-chip polarization beam splitter rotator to separate and transform the orthogonal polarization states of the incident light to obtain two optical signals with the same polarization state; utilizing the integrated optical spectrum analyzer based on a planar optical waveguide to separately process the two optical signals with the same polarization state, and then performing data fusion to realize integrated optical spectrum analysis with polarization analysis function.

[0024] (3) Beneficial effects

[0025] It can be seen from the above technical solutions that the integrated optical spectrum analyzer based on planar optical waveguide provided by the present invention and its application have the following beneficial effects:

[0026] 1. The integrated optical spectrum analyzer based on a planar optical waveguide provided by the present invention utilizes a periodic narrowband filtering module for fine filtering, a demultiplexing module for multi-band separation, a detector array for photoelectric conversion, and a control and data processing module for control and data processing. Through the coordinated operation of multiple modules, spectral analysis of light waves with different wavelength components can be achieved.

[0027] 2. The integrated optical spectrum analyzer based on planar optical waveguide provided by the present invention uses an integrated optical chip to realize the separation and detection of light waves of different wavelength components, thereby reducing the system volume.

[0028] 3. The integrated optical spectrum analyzer based on planar optical waveguide provided by the present invention adopts a combination of a narrow-band quasi-periodic filtering module and a demultiplexing module, which improves the spectral resolution on the one hand and the scanning speed on the other.

[0029] 4. The integrated optical spectrum analyzer based on planar optical waveguides provided by the present invention uses an integrated optical chip to separate and detect light waves of different wavelength components. It combines a narrowband quasi-periodic filtering module with a demultiplexing module. It has the advantages of small size, high integration, high resolution, and fast scanning speed. It can be used in systems such as miniaturized biochemical sensing equipment and portable optical tomography scanning imagers.

[0030] 5. The integrated optical spectrum analyzer based on the planar optical waveguide provided by the present invention can also realize an integrated optical spectrum analyzer with polarization analysis function by introducing a polarization light processing module, so that the integrated optical spectrum analyzer also has the function of light wave polarization state analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For a more complete understanding of the present invention and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

[0032] Figure 1 This is a typical implementation of an integrated optical spectrum analyzer based on a planar optical waveguide according to an embodiment of the present invention.

[0033] Figure 2 This is an implementation of a periodic narrowband filter module according to an embodiment of the present invention, which utilizes a special combination of two tunable microring resonators to improve its filtering resolution.

[0034] Figure 3 In another implementation of the periodic narrowband filter module according to an embodiment of the present invention, a tunable microdisk resonator and a tunable microring resonator are connected in series to improve the filtering resolution.

[0035] Figure 4 The tuning structure corresponds to a tuning method of a microring resonator and a microdisk resonator according to an embodiment of the present invention. By changing the voltage to bring about a temperature change in the waveguide area, the refractive index of the material is changed by the thermo-optical effect to achieve passband shift.

[0036] Figure 5 This is a tuning structure corresponding to another tuning method of the microring resonator and the microdisk resonator according to the embodiment of the present invention. By changing the voltage to change the carrier concentration in the waveguide area, the electro-optic effect is used to change the refractive index of the material to achieve passband shift.

[0037] Figure 6 A 2×2 Mach-Zehnder interferometer unit for implementing a demultiplexing module according to an embodiment of the present invention, and transmission spectra between different input and output ports thereof are shown.

[0038] Figure 7 The invention relates to a thermo-optical and electro-optical tuning structure of a 2×2 Mach-Zehnder interferometer. The structure changes the temperature or carrier concentration of the interference arm waveguide region by changing the voltage, and changes the material refractive index through the thermo-optical or electro-optical effect, thereby achieving passband shift.

[0039] Figure 8 The demultiplexing module structure according to the embodiment of the present invention is as follows: N-1 Mach-Zehnder interferometer unit is cascaded in the form of an N-level binary tree. By designing the arm length difference of the two interferometer arms of each Mach-Zehnder interferometer unit, a single path 2 can be separated. N The passband signal is 2 N Each output contains a passband.

[0040] Figure 9 This is the spectrum when the periodic narrowband filtering module and the demultiplexing module are synchronously tuned according to an embodiment of the present invention, that is, the passbands of the two are moved stepwise and synchronously.

[0041] Figure 10 The step of using a machine learning method to implement spectrum measurement is performed while the passband of the periodic narrowband filtering module is moved stepwise according to an embodiment of the present invention and the filtering characteristics of the demultiplexing module remain unchanged.

[0042] Figure 11 The structure of an integrated optical spectrum analyzer for realizing polarization analysis according to an embodiment of the present invention includes a polarization-independent optical coupler, a polarization beam splitter rotator, and two sets of the aforementioned integrated optical spectrum analyzers. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is obvious that one or more embodiments can also be implemented without these specific details. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0044] The present invention provides an integrated optical spectrum analyzer based on a planar optical waveguide. This integrated spectrum analyzer utilizes an integrated optical chip to separate and detect light waves of different wavelength components, reducing system size. Furthermore, this integrated spectrum analyzer combines a narrowband quasi-periodic filtering module with a demultiplexing module, improving both spectral resolution and scanning speed. Furthermore, by introducing a polarization processing module, this integrated spectrum analyzer also incorporates optical polarization state analysis capabilities.

[0045] The core of this invention's design lies in the combination of periodic, precise narrowband filtering and demultiplexing across a large free spectral range to achieve spectral analysis. Machine learning can also be used to reduce the difficulty of synchronous tuning. Furthermore, this invention can also perform polarization analysis of optical signals. It is applicable to both fiber-optic and free-space inputs. The beneficial results of this invention include: reduced system size and power consumption, lower control complexity, and richer functionality.

[0046] like Figure 1 As shown, Figure 1 This is a typical implementation of an integrated optical spectrum analyzer based on a planar optical waveguide according to an embodiment of the present invention. The integrated optical spectrum analyzer based on a planar optical waveguide includes a periodic narrowband filtering module 100, a demultiplexing module 200, a detector array 300, and a control and data processing module 400, wherein:

[0047] The periodic narrowband filtering module 100 is used to perform periodic narrowband filtering on the input optical signal to be measured to obtain a single-channel multi-passband narrowband optical signal;

[0048] The demultiplexing module 200 is used to separate the single-channel multi-pass narrowband optical signal received from the periodic narrowband filtering module 100, and separate the single-channel multi-pass narrowband optical signal into two N Each optical signal contains a passband, and each passband is output from a different output, where N ≥ 1;

[0049] The detector array 300 is used to detect the 2 N Convert optical signals into electrical signals and output them;

[0050] The control and data processing module 400 is used to control the periodic narrowband filtering module 100 and the demultiplexing module 200, so that the filter passband of the periodic narrowband filtering module 100 moves step by step, and the filter passband of the demultiplexing module 200 moves synchronously with the filter passband of the periodic narrowband filtering module 100. Each time it moves, the control and data processing module 400 receives 2 signals from the detector array 300. N The electrical signals are converted into analog-to-digital and processed, and after the movement is completed, the spectrum of the input optical signal is synthesized.

[0051] According to an embodiment of the present invention, Figure 1 In the periodic narrowband filtering module 100 shown, the periodic narrowband filtering module 100 is composed of a tunable micro-ring resonator unit, which receives the optical signal to be measured and performs periodic narrowband filtering on the received optical signal to be measured to obtain a single-channel multi-passband narrowband optical signal with a passband number of 2 NRing waveguide 110 and its two adjacent waveguides form a tunable microring resonator unit. By means of evanescent wave coupling, light waves can enter ring waveguide 110 through two adjacent waveguides, or they can enter two adjacent waveguides from ring waveguide 110 through evanescent wave coupling. Ring waveguide 110 can be circular, elliptical, racetrack-shaped, or any other closed optical waveguide loop.

[0052] Specifically, in the integrated optical spectrum analyzer based on planar optical waveguide provided in an embodiment of the present invention, the periodic narrowband filtering module 100 is composed of a combination of several tunable microring resonators, or a combination of several tunable microring resonators and tunable microdisk resonators, and includes one main function inlet as the input port of the optical signal, one main function outlet as the output port of the optical signal, and several auxiliary test ports for calibrating, calibrating and monitoring each component unit.

[0053] Due to the material dispersion and waveguide dispersion, the 2 output by the periodic narrowband filtering module 100 N In a narrowband optical signal, the wavelength interval Δλ between the center wavelength of the i-th passband and the center wavelength of the i+1-th passband i Non-fixed value, where 1≤i≤2 N -1, and its maximum value, minimum value and average value are respectively referred to as the maximum free spectral range, the minimum free spectral range and the average free spectral range of the periodic narrowband filtering module (100).

[0054] exist Figure 1 In the optical coupling array 500 and the periodic narrowband filter module 100 shown, the external optical signal to be measured is input from port 505 to port 101 of the periodic narrowband filter module 100. After the light wave enters the ring waveguide 110 through evanescent wave coupling, the light wave that meets its resonance condition will be transmitted to port 102, forming a multi-band, quasi-periodic narrowband optical signal; the light wave that does not meet the resonance condition of the ring waveguide 110 will be transmitted to port 103 and reach port 504. Meeting the resonance condition means that the integer multiple of the wavelength of the light wave is equal to the product of the effective refractive index of the waveguide at that wavelength and the circumference of the ring waveguide 110. The wavelength of light that meets the resonance condition is called the resonant wavelength. The wavelength of light that does not meet the resonance condition is called the non-resonant wavelength.

[0055] The average value of the distance between a resonant wavelength of a tunable microring resonator unit and its two nearest neighboring resonant wavelengths is called the equivalent free spectral range at the resonant wavelength. The size of the equivalent free spectral range is equal to FSR = λ 2 / (ng*L), where λ is the resonant wavelength, ng is the group refractive index corresponding to the wavelength, and L is the circumference of the ring waveguide 110. By designing the circumference of the ring waveguide 110, the average size of the equivalent free spectrum of the tunable microring resonator unit it constitutes is 1 / 2 of the entire spectrum range to be measured.N In this way, after the optical signal to be measured is input from the port 101 to the periodic narrowband filter module 100, it will be filtered to obtain 2 N A quasi-periodic narrowband optical signal is output from port 102.

[0056] exist Figure 1 In the figure, N=2, that is, the equivalent free spectrum area of ​​the periodic narrowband filtering module 100 is the average value of the mutual spacing of the central wavelengths of the four passbands obtained by filtering, which is 1 / 4 of the entire spectrum interval to be measured.

[0057] Port 101 is the main input port of periodic narrowband filter module 100, and port 102 is the main output port of 100. Ports 103 and 104 are auxiliary test ports of 100. The filtering spectrum from port 101 to port 102 is identical to the filtering spectrum from port 103 to port 104. Therefore, ports 103 and 104 can be used to calibrate, calibrate, and monitor periodic narrowband filter module 100, determining the relationship between filtering characteristics and applied drive.

[0058] According to an embodiment of the present invention, Figure 1 The demultiplexing module 200 consists of 2 N -1 Mach-Zehnder interferometer unit is cascaded in the form of an N-level binary tree, and the j-th level along the direction of optical transmission contains 2 (j-1) Mach-Zehnder interferometer units, where 1≤j≤N.

[0059] Optionally, the demultiplexing module 200 includes 2 N - a Mach-Zehnder interferometer unit for converting two of the multi-band, quasi-periodic narrowband optical signals from the periodic narrowband filtering module 100 into N The passband separation is 2 N Each independent optical signal has a passband and is output to a detector unit of the detector array 300.

[0060] Optionally, the demultiplexing module 200 can be implemented using a metasurface or subwavelength grating structure, including one main function entrance as an input port for optical signals, and two N The main function ports serve as the output ports of optical signals, and several auxiliary test ports are used to calibrate, calibrate and monitor the Mach-Zehnder interferometer unit.

[0061] Specifically, Figure 1In the specific example shown, N=2, so there are two stages of three 2×2 MZI units, namely, a first 2×2 MZI unit 210, a second 2×2 MZI unit 220, and a third 2×2 MZI unit 230. Each 2×2 MZI unit includes two 2×2 optical coupling units and two interferometer arms.

[0062] Taking the first 2×2 Mach-Zehnder interferometer 210 as an example, it includes a first 2×2 optical coupling unit 211, a second 2×2 optical coupling unit 212, a first interferometer arm 213 and a second interferometer arm 214. The first 2×2 optical coupling unit 211 and the second 2×2 optical coupling unit 212 each have two input ports and two output ports, which can be implemented by a directional coupler or a multi-mode interference coupler. The first interferometer arm 213 and the second interferometer arm 214 are interferometer arms of unequal lengths, and the length difference design principle is given below.

[0063] Figure 1 The arm length difference between the three 2×2 Mach-Zehnder interferometers in the ring waveguide 110 must satisfy the following relationship with the circumference of the ring waveguide 110 to achieve demultiplexing. The arm length difference between the first interferometer arm 213 and the second interferometer arm 214 is 1 / 2 of the circumference of the ring waveguide 110, making the free spectral range of the first 2×2 Mach-Zehnder interferometer 210 twice the equivalent free spectral range of the periodic narrowband filter module. The arm length difference between the third interferometer arm 223 and the fourth interferometer arm 224 is 1 / 4 of the circumference of the ring waveguide 110, making the free spectral range of the second 2×2 Mach-Zehnder interferometer 220 four times the equivalent free spectral range of the periodic narrowband filter module. The difference in arm length between the fifth interferometer arm 233 and the sixth interferometer arm 234 is 1 / 4 of the circumference of the ring waveguide 110, so that the free spectrum range of the third 2×2 Mach-Zehnder interferometer unit 230 is 4 times the equivalent free spectrum range of the periodic narrowband filtering module.

[0064] The function of the first 2×2 Mach-Zehnder interferometer 210 is to convert the 2×2 output of the periodic narrowband filter module 100 into N Quasi-periodic narrowband optical signals are separated in sequence (odd channel separation) into two quasi-periodic narrowband optical signals, each containing 2 N-1 To avoid insertion loss, a tuning structure is required on the first interferometer arm 213 and the second interferometer arm 214 of the first 2×2 Mach-Zehnder interferometer 210 so that the center wavelength of the filter passband of the first 2×2 Mach-Zehnder interferometer 210 is aligned with the center wavelength of the narrowband optical signal output by the periodic narrowband filter module 100.

[0065] The second 2×2 Mach-Zehnder interferometer 220 and the third 2×2 Mach-Zehnder interferometer 230 function to convert the two paths 2 output from the first 2×2 Mach-Zehnder interferometer 210 into N -1 wavelength signal is further separated into odd and even channels to obtain four optical signals, each containing 2 N -2 wavelengths. Figure 1 In the example, N=2, so a total of three 2×2 Mach-Zehnder interferometer units in two stages can separate the four-passband wavelength signals output by the periodic narrowband filtering module 100 .

[0066] For the general case, the demultiplexing module 200 consists of 2 N -1 2×2 Mach-Zehnder interferometer is cascaded in the form of N-level binary trees. The 2 i-1 The arm length difference of the 2×2 Mach-Zehnder interference unit is 1 / 2 of the circumference of the ring waveguide 110 i At least one interferometer arm of each Mach-Zehnder interferometer needs to include a tuning mechanism to achieve alignment with the center wavelength of the output passband of the previous stage.

[0067] According to an embodiment of the present invention, Figure 1 The detector array 300 includes 2 N A detector unit is used to receive the 2 separated signals from the demultiplexing module 200. N The optical signals are converted into electrical signals and output to the control and data processing module 400.

[0068] Optionally, the number of detector units in the detector array 300 is 2 N , which in turn are connected to the 2 of the demultiplexing module 200 N The output terminals are connected to each other to convert the output optical signal into a current signal. Figure 1 The detector array 300 includes four detector units, ie, N=2, including a first photodetector 301 , a second photodetector 302 , a third photodetector 303 , and a fourth photodetector 304 , a total of four photodetectors.

[0069] According to an embodiment of the present invention, Figure 1 The control and data processing module 400 in the embodiment moves the periodic narrowband filter module 100 and the demultiplexing module 200 by a certain distance Δλ in the same direction each time the periodic narrowband filter module 100 and the demultiplexing module 200 are moved. s Each time it moves, the detector array 300 outputs 2 N Photocurrent; a total of M-1 moves to obtain M×2 NPhotocurrent data, where M>1; the value of M satisfies the following relationship: (M-1)×Δλ s < the maximum free spectral range of the periodic narrowband filter module 100, and M×Δλ s ≥The maximum free spectral range of the periodic narrowband filter module 100.

[0070] Specifically, the control and data processing module 400 has 2 N Each time, it receives 2 N analog electrical signals, received M times to obtain M×2 N electrical signals, for this M×2 N The electrical signal is converted into analog and digital form and the data is processed.

[0071] When the filter passband of the periodic narrowband filter module 100 is moved in steps, the filter passband of the demultiplexing module 200 does not follow the movement; when an optical signal with known spectral information is input, only the periodic narrowband filter module 100 is scanned and tuned to obtain the output of the detector array 300; using machine learning methods, by changing the spectrum of the input optical signal, a large number of input and output combinations are obtained, which are used to train the neural network, so that the integrated optical spectrum analyzer can obtain the spectrum of the optical signal to be measured through the trained neural network when the demultiplexing module 200 does not follow the tuning of the periodic narrowband filter module 100.

[0072] Furthermore, Figure 1 The integrated optical spectrum analyzer based on the planar optical waveguide shown in the figure also includes: an optical coupling array 500, which is used to couple the light from the optical fiber array or free space to the periodic narrowband filter module 100. The optical coupling array 500 can be a mode spot conversion end face coupler, or a one-dimensional grating coupler or a two-dimensional grating coupler. If it is a two-dimensional grating coupler, the subsequent unit connection relationship will be described in Figure 11 Detailed explanation in .

[0073] Figure 2 This is an implementation of a periodic narrowband filter module according to an embodiment of the present invention, which utilizes a special combination of two tunable microring resonators to improve its filtering resolution. Figure 2 The overall structure shown above completes the periodic narrowband filtering function, which can replace Figure 1 The periodic narrowband filtering module 100 in FIG.

[0074] Figure 2The tunable microring resonator 100 in FIG. 1 includes a first ring waveguide 101, two intersecting second and third proximity waveguides 102 and 103. Optical energy is exchanged between the first and second proximity waveguides 102, and between the first and third proximity waveguides 103, via evanescent coupling. The boundary between the second and third proximity waveguides 102 and 103 is defined by a dashed box. The upper port of the third proximity waveguide 103 is connected to the right port of the second proximity waveguide 102 via waveguide 301.

[0075] Figure 2 The tunable microring resonator 200 includes a second ring waveguide 201, two parallel second waveguides 202 and a third waveguide 203, and both the second waveguide 202 and the third waveguide 203 are adjacent to the second ring waveguide 201. The boundary between the second waveguide 202 and the third waveguide 203 is defined by a dashed box. The left port of the third waveguide 203 is connected to the lower port of the third adjacent waveguide 103 via a connecting waveguide 302.

[0076] Figure 2 The main input port of the periodic narrowband filter module 100 is 401, and the main output port is 402. The third port 403 and the fourth port 404 are auxiliary test ports. The transmission spectrum from the main input port 401 to the lower port of the third adjacent waveguide 103 is as follows: Figure 2 The transmission spectrum from the left port of the third waveguide 203 to the main output port 402 is shown in the middle curve 501, which is characterized by a narrow passband in a dipped transmission spectrum. Figure 2 The middle curve 502 is a bandpass spectrum, which is the standard spectrum of a common up-down microring resonator. The transmission spectrum from the main input port 401 to the main output port 402 is shown in FIG. Figure 2 As shown by the middle curve 503, its passband width is smaller than the passband widths of curves 501 and 502. To achieve this narrowband filtering effect, it is necessary to design the geometric dimensions of the first ring waveguide 101 and the second ring waveguide 201, their spacing from adjacent waveguides, and align their resonant wavelengths. Therefore, both need to include tuning mechanisms.

[0077] Figure 3 In another implementation of the periodic narrowband filter module according to an embodiment of the present invention, a tunable microdisk resonator and a tunable microring resonator are connected in series to improve the filtering resolution. Figure 3 The overall structure shown above completes the periodic narrowband filtering function, which can replace Figure 1 The periodic narrowband filtering module 100 in FIG.

[0078] Figure 3The tunable microdisk resonator 100 in FIG. 1 comprises a disk waveguide 101, two intersecting second and third proximity waveguides 102 and 103. Evanescent coupling is used to exchange optical energy between the disk waveguide 101 and the second and third proximity waveguides 102, respectively. The boundary between the second and third proximity waveguides 102 and 103 is defined by a dashed box. The upper port of the third proximity waveguide 103 is connected to the right port of the second proximity waveguide 102 via a connecting waveguide 301.

[0079] Figure 3 The tunable microring resonator 200 includes a second ring waveguide 201, two parallel second waveguides 202 and a third waveguide 203, and both the second waveguide 202 and the third waveguide 203 are adjacent to the second ring waveguide 201. The boundary between the second waveguide 202 and the third waveguide 203 is defined by a dashed box. The left port of the third waveguide 203 is connected to the lower port of the third adjacent waveguide 103 via a connecting waveguide 302.

[0080] Figure 3 The main input port of the periodic narrowband filter module 100 is 401, and the main output port is 402. The third port 403 and the fourth port 404 are auxiliary test ports. The transmission spectrum from the main input port 401 to the lower port of the third adjacent waveguide 103 is as follows: Figure 3 The transmission spectrum from the left port of the third waveguide 203 to the main output port 402 is shown in the middle curve 501, which is characterized by a narrow passband in a dipped transmission spectrum. Figure 3 The middle curve 502 is a narrowband passband signal, which is the standard spectrum of a common uplink / downlink microring resonator. The transmission spectrum from the main input port 401 to the main output port 402 is shown in FIG. Figure 3 As shown by the middle curve 503, its passband width is smaller than the passband widths of curves 501 and 502. To achieve this narrowband filtering effect, it is necessary to design the geometric dimensions of the disk waveguide 101 and the second ring waveguide 201, their spacing from adjacent waveguides, and align their resonant wavelengths. Therefore, both need to include tuning mechanisms.

[0081] Figure 4 FIG. 1 is a tuning structure corresponding to a tuning method of a microring resonator and a microdisk resonator according to an embodiment of the present invention, wherein only the ring waveguide and the disk waveguide are shown, and the adjacent waveguides are not shown. Figure 4The first ring waveguide 101, third ring waveguide 301, fifth ring waveguide 501, and seventh ring waveguide 701 are ring waveguides, while the second disk waveguide 201, fourth disk waveguide 401, sixth disk waveguide 601, and eighth disk waveguide 801 are disk waveguides. By varying the voltage to change the temperature of the ring waveguides and disk waveguides, the refractive index of the material is altered by the thermo-optical effect, achieving passband shift.

[0082] Figure 4 Among them, 102, 103, 104, 302, 303, 304, 502, 503, 504 are hot-pole metals, which are made of metals such as titanium nitride TiN or titanium tungsten alloy TiW. The hot-pole metal 102 is located directly above the first ring waveguide 101. The radius of the hot-pole metal 302 is smaller than that of the first ring waveguide 101. The radius of the hot-pole metal 502 is larger than that of the first ring waveguide 101. The hot-pole metals 103, 104, 303, 304, 503, 504 need to be covered with dielectrics such as silicon dioxide and silicon nitride, and then through patterning, etching, metal pouring and other processes, vias, leads and pins are formed to realize electrical connection of the drive signal. Vias, leads and pins are not in Figure 4 Displayed in.

[0083] Figure 4 Among them, 202, 203, 204, 402, 403, 404, 602, 603, and 604 are hot-pole metals, which are made of metals such as titanium nitride TiN or titanium tungsten alloy TiW. The hot-pole metal 202 is located directly above the outer edge of the second disk-shaped waveguide 201. The radius of the hot-pole metal 402 is smaller than the outer radius of the second disk-shaped waveguide 201. The radius of the hot-pole metal 602 is larger than the outer radius of the second disk-shaped waveguide 201. The hot-pole metals 203, 204, 403, 404, 603, and 604 need to be covered with dielectrics such as silicon dioxide and silicon nitride, and then graphic processing, etching, metal pouring and other processes are used to form vias, leads and pins to realize electrical connection of the drive signal. Vias, leads, and pins are not in Figure 4 Displayed in.

[0084] exist Figure 4 When voltage is applied between 103 and 104, 203 and 204, 303 and 304, 403 and 404, 503 and 504, and 603 and 604, the corresponding hot electrode metals 102, 202, 302, 402, 502, and 602 heat up, causing the temperatures of the first ring waveguide 101, the second disk waveguide 201, the third ring waveguide 301, the fourth disk waveguide 401, the fifth ring waveguide 501, and the sixth disk waveguide 601 to rise. The magnitude of the temperature rise is positively correlated with the applied voltage. This temperature change causes a change in the refractive index of the waveguide material, which in turn shifts the resonant wavelength, thereby shifting the filter passband.

[0085] The thermo-optical effect can also be achieved by not using thermocouple metals but by using ion implantation to form resistors. Figure 4 The seventh ring waveguide 701 and the eighth disk waveguide 801 are ring waveguide and disk waveguide, respectively. 702, 703, 704, 802, 803, 804 are doped regions. By controlling the doping dose and energy of ion implantation, a suitable resistance value is obtained, generally ranging from tens of ohms to thousands of ohms.

[0086] Figure 4 The doped regions 703, 704, 803, and 804 in the circuit need to undergo windowing, heavy doping, covering with dielectrics such as silicon dioxide or silicon nitride, opening vias, pouring metal, patterning, and etching to form leads and pins. Figure 4 The doped regions 703, 704, 803, 804 in FIG.

[0087] exist Figure 4 When voltage is applied between doped regions 703 and 704, and between doped regions 803 and 804, the corresponding doped regions 702 and 802 heat up due to the ohmic heating effect, causing the temperature of the seventh ring waveguide 701 and the eighth disk waveguide 801 to rise. The magnitude of the temperature rise is positively correlated with the applied voltage. This temperature change causes a change in the refractive index of the waveguide material, which in turn shifts the resonant wavelength, thus shifting the filter passband.

[0088] Figure 5 This is a tuning structure corresponding to another tuning method of the microring resonator and the microdisk resonator according to the embodiment of the present invention. By changing the voltage to change the carrier concentration in the waveguide area, the electro-optic effect is used to change the refractive index of the material to achieve passband shift.

[0089] Figure 5 In the figure, 101 and 201 are ring waveguide and disk waveguide respectively. Regions 102, 103, and 104 are doped with the same polarity (p-type or n-type), while region 105 is doped with the opposite polarity (n-type or p-type). Between the two doped regions is the intrinsic region occupied by the ring waveguide 101, called the i-region. The three form a pin structure. Re-doping with corresponding polarity is performed on 103, 104, 105, 203, 204, and 205, and then covered with a dielectric such as silicon dioxide or silicon nitride, vias are opened, metal is poured, patterned, and etched to form leads and pins. By applying different voltages to the p-region and the n-region, the carrier concentration in the i-region where the waveguide is located can be changed, thereby changing the refractive index of the material, resulting in a change in the resonant wavelength, that is, achieving a shift in the filter passband.

[0090] Figure 6A 2×2 Mach-Zehnder interferometer unit for implementing a demultiplexing module according to an embodiment of the present invention, and the transmission spectra between its different input and output ports. In this 2×2 Mach-Zehnder interferometer unit, the first 2×2 multimode interference coupler 101 and the second 2×2 multimode interference coupler 102 each have four ports. The third port 303 and the fifth port 305 are connected via the second waveguide 202. The fourth port 304 and the sixth port 306 are connected via the first waveguide 201. The length difference between the first waveguide 201 and the second waveguide 202 determines the free spectral range of the 2×2 Mach-Zehnder interferometer unit.

[0091] The 2×2 multimode interference coupler in the 2×2 Mach-Zehnder interferometer unit can also be replaced by a 2×2 directional coupler. The first 2×2 directional coupler 501 and the second 2×2 directional coupler 502 each have four ports. Port 603 and port 605 are connected via waveguide 502. Port 604 and port 606 are connected via waveguide 501. The length difference between waveguides 501 and 502 determines the free spectral range of the 2×2 Mach-Zehnder interferometer unit.

[0092] The optical energy of the light wave input from the first port 301 is evenly distributed between the third port 303 and the fourth port 304. The optical energy of the light wave input from the second port 302 is evenly distributed between the third port 303 and the fourth port 304. The optical energy of the light wave input from the fifth port 305 is evenly distributed between the seventh port 307 and the eighth port 308. The optical energy of the light wave input from the sixth port 306 is evenly distributed between the seventh port 307 and the eighth port 308.

[0093] The optical energy of the light wave input from port 601 is evenly distributed between ports 603 and 604. The optical energy of the light wave input from port 602 is evenly distributed between ports 603 and 604. The optical energy of the light wave input from port 605 is evenly distributed between ports 607 and 608. The optical energy of the light wave input from port 606 is evenly distributed between ports 607 and 608.

[0094] Figure 6 Spectral line 701 in FIG. 1 is the transmission spectrum from first port 301 to third port 303. Light with wavelengths 801, 803, 805, and 807 is transmitted with low loss, while light with wavelengths 802, 804, 806, and 808 does not reach third port 303 and is instead transmitted to fourth port 304. The average spacing between the maxima (or minima) of spectral line 701 is the free spectral range of the 2×2 Mach-Zehnder interferometer cell, which is inversely proportional to the interferometer arm length difference.

[0095] Figure 6Spectral line 702 in FIG. is the transmission spectrum from first port 301 to fourth port 304. Light with wavelengths 802, 804, 806, and 808 is transmitted with low loss, while light with wavelengths 801, 803, 805, and 807 does not reach fourth port 304 and is instead transmitted to third port 303. The average spacing between the maxima (or minima) of spectral line 702 is the free spectral range of the 2×2 Mach-Zehnder interferometer cell, which is inversely proportional to the interferometer arm length difference.

[0096] If light with wavelengths of 801 to 808 comes directly from the periodic narrowband filter module 100, then the average spacing between 801 and 808 is the equivalent free spectral range of the periodic narrowband filter module 100. This shows that the free spectral range of the first-stage Mach-Zehnder interferometer is twice the equivalent free spectral range of the periodic narrowband filter module. The free spectral range of the next-stage Mach-Zehnder interferometer is twice the free spectral range of the previous-stage Mach-Zehnder interferometer.

[0097] Figure 7 This is a thermo-optical and electro-optical tuning structure for a 2×2 Mach-Zehnder interferometer according to an embodiment of the present invention, in which passband shifting is achieved by changing the voltage. 101 and 102 are the thermo-optically tuned portions of the two interferometer arms, and 201 and 202 are thermopole metals. Alternatively, only one interferometer arm may be thermo-optically tuned, such as 301 being the thermo-optically tuned portion of one interferometer arm, 401 being the thermopole metal, and 302 being the untuned interferometer arm. 501 and 502 are the electro-optically tuned portions of the two interferometer arms, 601 and 701 being doped regions of two different polarities, and 602 and 702 being doped regions of two different polarities. Alternatively, only one interferometer arm may be electro-optically tuned, such as 801 being the electro-optically tuned portion of one interferometer arm, 901 and 1001 being doped regions of two different polarities, and 802 being the untuned interferometer arm.

[0098] Figure 8 The demultiplexing module 200 according to the embodiment of the present invention is constructed in the form of a structure, wherein 2 N -1 2×2 Mach-Zehnder interferometer unit is cascaded in the form of N-level binary tree. By designing the wavelength difference of each Mach-Zehnder interferometer unit, 2 N A passband signal.

[0099] The single-channel multi-wavelength narrowband signal from the periodic narrowband filtering module 100 contains 2 N wavelength components, and the channel spacing is Δλ. The i-th level contains 2 (i-1) Mach-Zehnder interferometer units, whose free spectral range is 2 i ×Δλ, output 2 i optical signals, each of which has 2 (N-i) wavelength components. The total number of the i-th level is 2(i-1) There are three Mach-Zehnder interferometer units. One input port of each unit receives a path of light from the previous stage, and the other port is used as a test port to independently calibrate the filter spectrum of each Mach-Zehnder interferometer unit, that is, to determine the relationship between the change of each filter spectrum line and the working voltage. One of the entrances of each Mach-Zehnder interferometer unit is used as a test port, but the exits are all connected to the next stage. Therefore, it is necessary to use a directional coupler at the exit to extract a small amount of light (generally less than 5%) for the calibration of the Mach-Zehnder interferometer unit. For specific methods and instructions, see Figure 9 and its explanation.

[0100] Figure 9 The input and output spectra of a 2×2 Mach-Zehnder interferometer unit are shown when the periodic narrowband filtering module 100 and the demultiplexing module 200 are synchronously tuned according to an embodiment of the present invention, that is, when the passbands of the two are moved stepwise and synchronously.

[0101] exist Figure 9 In the example, eight narrowband optical signals (101 to 108) enter from port 005. This signal can be the direct output of the periodic narrowband filter module, or it can be transmitted to port 005 after passing through the 2×2 Mach-Zehnder interferometer unit at other stages in the demultiplexing module. By tuning the third interferometer arm 003 and the fourth interferometer arm 004, the transmission spectrum from port 005 to port 011 of the 2×2 Mach-Zehnder interferometer unit can be made as follows: Figure 9 As shown in the spectrum line 200, wavelength components 101, 103, 105, and 107 are transmitted to port 011 with low loss, while wavelength components 102, 104, 106, and 108 are transmitted to port 012 with low loss.

[0102] When the control and data processing module 400 controls the periodic narrowband filter module 100 and the demultiplexing module 200 to synchronize, the wavelength of the light input to the port 005 will shift by Δλ s , moving Δλ from 101 to 108 s To 201 to 208. Figure 9 The third interferometer arm 003 and the fourth interferometer arm 004 of the 2×2 Mach-Zehnder interferometer unit need to be tuned accordingly so that their passband centers are aligned with 201 to 208, as shown by the spectrum line 400 in the figure. s The size depends on the bandwidth of each passband of the periodic narrowband filter module. The smaller the bandwidth, the greater the Δλ s The smaller it is. s The size of is selected as the largest one among all the passband bandwidths of the periodic narrowband filtering module.

[0103] Figure 9Port 017 is a directional coupler structure, extracting up to 5% of the light from the optical waveguides 011 to 013 to port 016. Ports 006 and 016 can be used as input and output ports for calibration, evaluation, and monitoring of the 2×2 Mach-Zehnder interferometer. To balance link loss, a directional coupler with the same parameters as directional coupler 017 can be added between ports 012 and 014.

[0104] Figure 10 The step of using a machine learning method to implement spectrum measurement is performed while the passband of the periodic narrowband filtering module is moved stepwise according to an embodiment of the present invention and the filtering characteristics of the demultiplexing module remain unchanged.

[0105] The basic idea is to use machine learning to input an optical signal with a known spectrum. The periodic narrowband filter module is step-tuned, while the demultiplexer module remains untuned. The output of the detector array is acquired and stored. Different known spectra are then input to obtain the corresponding detector data. This dataset is then used to train a neural network. If the trained model is not accurate enough, it can be retrained.

[0106] In this operating mode, the demultiplexing module can be implemented not by a Mach-Zehnder interferometer but by structures such as metamaterials, metasurfaces, and subwavelength gratings. The implementation of the demultiplexing module also affects the sample size required for the aforementioned machine learning and the prediction accuracy of the neural network.

[0107] Furthermore, in actual applications, the periodic narrowband filtering module 100, the demultiplexing module 200, and the detector array 300 can be implemented as a monolithic integrated chip and prepared through compatible processes on a common substrate material; or the periodic narrowband filtering module 100, the demultiplexing module 200, and the detector array 300 can be implemented by independent chips respectively and integrated into a system through packaging.

[0108] based on Figures 1 to 10 The embodiment of the present invention further provides an application of the integrated optical spectrum analyzer based on the planar optical waveguide, specifically including:

[0109] Step S1: receiving external input light using a polarization-independent end coupler;

[0110] Step S2: Using an on-chip polarization beam splitter and rotator, the orthogonal polarization states of the incident light are separated and transformed to obtain two optical signals with the same polarization state;

[0111] Step S3: using the integrated optical spectrum analyzer based on the planar optical waveguide to process the two optical signals with the same polarization state respectively, and then performing data fusion to realize the integrated optical spectrum analysis with polarization analysis function.

[0112] Regarding the application of the above-mentioned integrated spectrum analyzer, Figure 11 The structure of an integrated optical spectrum analyzer for realizing polarization analysis according to an embodiment of the present invention involves a polarization-independent optical coupler, a polarization beam splitter rotator, a two-dimensional grating coupler, and two sets of the aforementioned integrated optical spectrum analyzers.

[0113] The first approach uses a polarization-independent end-face optical coupler to receive incoming light, either from an optical fiber or free-space sources. This coupler maintains the polarization components of the original light field and transmits them to a polarization beam splitter. The polarization beam splitter separates the two orthogonal polarization components of the incoming light, rotating the first by 90 degrees to the same polarization state as the first. The two beams, each with the same polarization state and meeting the requirements of the subsequent integrated spectrometer, enter their respective integrated optical spectrum analyzers. The resulting spectral data is then aggregated and analyzed to produce spectral data containing polarization information.

[0114] The second approach uses a two-dimensional grating coupler to receive incoming light, either from an optical fiber or from free space. The characteristic of a two-dimensional grating coupler is that, while coupling light, it automatically orthogonally separates the polarization into two consistent polarization states, which are then fed into a planar optical waveguide. The polarization states of these two separated beams meet the requirements of the subsequent integrated spectrometer, and each beam enters its own integrated optical spectrum analyzer. The resulting spectral data is then aggregated and analyzed to produce spectral data containing polarization information.

[0115] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0116] Furthermore, the shapes and sizes of the components in the figures do not reflect the actual sizes and proportions, but are merely illustrative of the contents of the embodiments of the present disclosure. In addition, in the claims, any reference signs placed between brackets should not be construed as limiting the claims.

[0117] The core of this design lies in the combination of periodic, precise narrowband filtering and demultiplexing across a large free spectral range to achieve spectral analysis. Machine learning can also be used to reduce the difficulty of synchronous tuning. Furthermore, this solution can also include polarization analysis of the optical signal. This solution is applicable to both fiber and free-space inputs. The benefits of this solution include reduced system size and power consumption, lower control complexity, and richer functionality.

Claims

1. An integrated optical spectrum analyzer based on planar optical waveguide, characterized in that: include: A periodic narrowband filtering module (100) is used to perform periodic narrowband filtering on the input optical signal to be measured to obtain a single-channel multi-passband narrowband optical signal; A demultiplexing module (200) is used to separate the single-channel multi-pass narrowband optical signal received from the periodic narrowband filtering module (100), and to separate the single-channel multi-pass narrowband optical signal into two N Each optical signal contains a passband, and each passband is output from a different output, where N ≥ 1; The detector array (300) is used to separate the 2 N Convert optical signals into electrical signals and output them; as well as The control and data processing module (400) is used to control the periodic narrowband filtering module (100) and the demultiplexing module (200), so that the filter passband of the periodic narrowband filtering module (100) moves in a step-by-step manner, and the filter passband of the demultiplexing module (200) moves synchronously with the filter passband of the periodic narrowband filtering module (100), and each time the control and data processing module (400) moves, the 2 received from the detector array (300) N The electrical signal is converted into analog and processed, and after the movement is completed, the spectrum of the input optical signal is synthesized; Wherein, when the control and data processing module (400) controls the movement of the periodic narrowband filtering module (100) and the demultiplexing module (200), each time the movement is performed, the filter passband positions of the periodic narrowband filtering module (100) and the demultiplexing module (200) are moved in the same direction by a certain distance Δλ s Each time it moves, the detector array (300) outputs 2 N A photocurrent.

2. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The periodic narrowband filtering module (100) is composed of a tunable micro-ring resonator unit, receives the optical signal to be measured, and performs periodic narrowband filtering on the received optical signal to be measured to obtain a single-channel multi-passband narrowband optical signal with a passband number of 2 N .

3. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The periodic narrowband filter module (100) is composed of a combination of several tunable micro-ring resonators, or a combination of several tunable micro-ring resonators and tunable micro-disk resonators, and comprises a main function inlet as an input port for optical signals, a main function outlet as an output port for optical signals, and several auxiliary test ports for calibrating, calibrating and monitoring each component unit.

4. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: Due to the material dispersion and waveguide dispersion, the periodic narrowband filtering module (100) outputs 2 N In a narrowband optical signal, the wavelength interval Δλ between the center wavelength of the i-th passband and the center wavelength of the i+1-th passband i Non-fixed value, where 1≤i≤2 N -1, and its maximum value, minimum value, and average value are respectively referred to as the maximum free spectral range, the minimum free spectral range, and the average free spectral range of the periodic narrowband filtering module (100).

5. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The demultiplexing module (200) consists of 2 N -1 Mach-Zehnder interferometer is cascaded in the form of an N-level binary tree, and the j-th level along the direction of optical transmission contains 2 (j-1) Mach-Zehnder interferometer units, where 1≤j≤N.

6. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The demultiplexing module (200) includes 2 N - a Mach-Zehnder interferometer unit for converting two of the multi-passband, quasi-periodic narrowband optical signals from the periodic narrowband filtering module (100) into N The passband separation is 2 N Each path includes a passband and is output to a detector unit of the detector array (300).

7. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 5 or 6, characterized in that: The demultiplexing module (200) is implemented using a metasurface and sub-wavelength grating structure, and includes a main function entrance as an input port for optical signals, and two N The main function ports serve as the output ports of optical signals, and several auxiliary test ports are used to calibrate, calibrate and monitor the Mach-Zehnder interferometer unit.

8. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The detector array (300) includes 2 N A detector unit for receiving the 2 separated N The optical signals are converted into electrical signals and output to the control and data processing module (400).

9. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: When the control and data processing module (400) controls the movement of the periodic narrowband filtering module (100) and the demultiplexing module (200), the control and data processing module (400) moves M-1 times to obtain M×2 N Photocurrent data, where M>1; the value of M satisfies the following relationship: (M-1)×Δλ s < the maximum free spectral range of the periodic narrowband filter module (100), and M×Δλ s ≥ the maximum free spectral region of the periodic narrowband filter module (100).

10. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The control and data processing module (400) has 2 N Input, each receiving 2 from the detector array (300) N analog electrical signals, received M times to obtain M×2 N electrical signals, for this M×2 N The electrical signal is converted into analog and digital and data processed.

11. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: When the filter passband of the periodic narrowband filter module (100) moves in a step-by-step manner, the filter passband of the demultiplexing module (200) does not follow the movement; Inputting an optical signal with known spectral information, and scanning and tuning only the periodic narrowband filter module (100) to obtain the output of the detector array (300); By using a machine learning method, a large number of input and output combinations are obtained by changing the spectrum of the input optical signal, and the combinations are used to train a neural network, so that the integrated optical spectrum analyzer can obtain the spectrum of the optical signal to be measured through the trained neural network when the demultiplexing module (200) does not follow the tuning of the periodic narrowband filtering module (100).

12. The integrated optical spectrum analyzer based on planar optical waveguide according to claim 1, characterized in that: The periodic narrowband filtering module (100), the demultiplexing module (200), and the detector array (300) are monolithic integrated chips, and are manufactured on a common substrate material through compatible processes; or The periodic narrowband filtering module (100), the demultiplexing module (200), and the detector array (300) are respectively implemented by independent chips and are integrated into a system through packaging.

13. Application of the integrated optical spectrum analyzer based on planar optical waveguide according to any one of claims 1 to 12, characterized in that: include: Using a polarization-independent end-face coupler to receive external input light; The on-chip polarization beam splitter and rotator is used to separate and transform the orthogonal polarization states of the incident light to obtain two optical signals with the same polarization state. The integrated optical spectrum analyzer based on the planar optical waveguide according to any one of claims 1 to 12 is used to process two optical signals with the same polarization state respectively, and then perform data fusion to realize integrated optical spectrum analysis with polarization analysis function.

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